Will My Roof Collapse?
The depth of snow is not the critical factor that determines whether your roof is at risk of collapse. It is the weight of the snow. Snow can weigh from 3 pounds per square foot (the light and fluffy kind) to 21 pounds per square foot depending upon the amount of water retained in the snow. Ice can be a staggering 57 pounds per square foot!
How much can your roof hold?
Roof construction, age, and condition play a large role in determining the strength of your roof. The type and grade of lumber used, as well as poor or inferior products and materials can also affect the overall condition. State building codes currently require residential roofs to be able to withstand snow loads of at least 30 pounds per square foot. A home constructed 40 years ago may not have been designed to handle the same snow loads of newer construction and may have a much higher risk of collapse.
Should you remove it?
If your home has low-pitched rooflines, the probability of snow overload is much higher. A steeply pitched roof enables the snow to slide or fall off more easily.
A good rule of thumb: If you have more than 18 inches of snow on your roof, it is a good indicator that the snow should be removed. Even if it is only the light and fluffy kind, a solid rainfall and frigid temperatures could dramatically increase the weight on your roof, making for a much more serious situation.
Other indicators are sagging roof rafters, sagging ceiling tiles, jammed doors and windows, cracked ceilings, a leaking roof, and popping, creaking or snapping noises. The popping, creaking or snapping sounds are definite warning signs that there is too much weight on your roof. These noises are cause for alarm and should be followed up with an inspection by a reputable professional. If the noises are loud and persistent, it is best to evacuate your home and call in a professional to evaluate the situation.
How do you remove the snow SAFELY?
Should you decide to take matters into your own hands, homeowners can use a roof rake to clear the snow. The most effective way to use a roof rake is to begin by clearing the overhangs first and proceed to pull off about a foot or so at a time from the bottom. Should you decide to start higher up on the roof, you take the chance of packing the snow left behind. This snow removal method works great for single-story homes and for reaching overhangs. It certainly has its limitations with multi-story homes and varying rooflines. But, be very wary of falling ice and overhead power lines. Many older homes have low-lying power lines attached to the home. Metal poles and power lines are not friends!
Shoveling can pick up where raking left off. Should you attempt to climb out to your roof to shovel it off, you must consider the pitch of the roof. Flat roofs, as long as they are structurally sound, are the safest bet. But it is still very important that you take safety into consideration. Stay clear of overhead power lines, and leave it to the professionals if the roof is covered with ice. A roof can be slippery, and every year, hundreds of people are injured or killed from falling off roofs. The safest alternative in this situation is to contact the professionals. A contractor or roofing company will both offer roof-clearing services.
If you are unsure about your course of action, your safest choice is to bring in the professionals. Just make sure that the professionals are licensed and insured!